<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .parent{
            border:  2px solid #333;
            width: 100px;
            height: 100px;

            /* text-align: center;
            line-height: 100px; */
          

           /* display: flex;
           flex-direction:row;
           justify-content: center;
           align-items: center; */


           position: relative;

        }
        .test{
            position: absolute;
            left: 50%;
            top: 50%;
            margin-top: -25px;
            margin-left: -25px;
            width: 50px;
            height: 50px;
            background-color: pink;
          

            display: inline-block;
            vertical-align: middle;
         
            
        }

    </style>
</head>
<body>
    <div class="parent">
        <div class="test"></div>
    </div>
</body>
</html>